I am upgrading from ArcGIS desktop 10.0 to 10.1 and I have a bunch of addins developed in VS 2008 Express using ArcObjects 10.0. I would like to upgrade everything to 10.1 using VS 2010 Express. I understand that for ArcGIS Desktop .NET Framework 3.5 Service Pack 1 is still required.

I converted my first existing addin to 10.1 in VS 2010 Express but it seems to be targeting .Net 4.0. I only found instructions on changing the target version in full version of VS but I can't find this feature in the Express edition. Can someone shed some light on this?

EDIT: I am adding a screenshot from Project -> Project Properties -> Application to show where I would expect to change the Target Framework but I don't see where it could be changed.